ya i think the big myth with 3d printing is that you can click a few buttons and you are able to print anything you want regardless of design, but the 3d printing process with all printers has its limitations, whether it is accuracy, support material, strength of the part, etc. I am just trying to works with this printer that we have and am interested to find out what the printer does differently when using different fibers, cause to me it seems an awful lot like it does the same thing regardless of whether it is using kevlar, glass, and carbon fiber. however, kevlar comes out on the kevlar setting and carbon does not even though the print head is the same temperature.
Also I don’t really understand the difference between the mark one and the mark two, except they say the mark two can print faster of something. but it doesn’t seem like they changed the hardware a whole lot, I could be wrong
Presumably its Eiger that will not allow you to do that… as I said above the software will only print the carbon in long length’s and I assume that when kevlar or glass settings are selected the software by default will not allow the carbon to extrude… I only had mine for a week so I’m certainly no expert… it’s probably better to ask your vendor or better still the manufacturer.
I think you are probably right… personally I think there’s a lot of ‘smoke & mirrors’ surrounding this printer and I was very glad to have got rid of it…
I’ve not run this machine, but did look at buying one last year to compliment our other machines, so understand the fundamentals. When you load carbon fibre, (and use Kevlar settings) does it know which material is loaded?
only if you haven’t surreptitiously switched the labels on the filament spools
joking of course… I think it’s more to do with your design and the Eiger (software) settings… if you are trying to print something smaller than the default length/parameter for carbon printing then the carbon will simply not print… and it doesn’t tell you that it won’t either so you just end up with a nylon model. Also no one actually tells you that when you buy it.
P.S. Also don’t forget that the filaments are proprietary and very expensive… £200 for nylon and £120 for carbon…
I think you’re right. There are some restrictions on where it can apply the carbon strands. It’s a fantastic concept, best suited to thicker geometries. Out of interest, how do those prices equate to £/kg?
obviously i think that you are spot on: i’ll probably have to call markforged and ask them myself, which shouldn’t be too difficult. However i still don’t think that is the issue either because my “test part” that we have been working with (a super basic rectangular prism) certainly works with all different fibers in all different directions. I’ve already printed kevlar in the isotropic settings with this part and it works fine. however as soon as i unload the kevlar, load the carbon and change nothing else, all of a sudden it is not printing the fiber. It tried to load the fiber and extrude it (the fiber tube is transparent so you can see exactly what is going on with the fiber) but when the fiber reached the nozzle it stopped and no fiber was coming out of the nozzle. I don’t know why it would do this, but again it was working with the kevlar originally so the mystery continues
I do still think it has its unique uses though… its moreover that they are trying to sell it as a consumer multi-use type printer which from my experience it is not… as part of a 3D print farm it may well be invaluable but it is still pretty much model/design specific… looks absolutely amazing in your front room/office if you’re looking to impress of course…
That is interesting… maybe it does actually have some kind of sensor fitted because they knew we would try to do exactly what you are attempting to do… would definitely be interesting to find out the response from MarkForged… keep us updated.
Perhaps you really should try surreptitiously switching the labels on the filament spools
Carbon Fiber is too stiff to make the sharp turns that the machine can make with either fiber glass or Kevlar. Hence the reduced options in the Carbon Fiber menu.
I was a bit disappointed by this as well with my Mark One. Pretty sure the limitation is due to the brittle nature of carbon fiber. Dig into you composites text books. You will find that there is a minimum radius of curvature that you can bend a brittle fiber around before it breaks. It is a function of the individual fiber diameter, modulus, and strain capability of the fiber. Markforged does not really tell you what the exact fiber they use. So exact fiber modulus, fiber diameter, strain capability are hard to come by. Isotropic Fiber mode has to bend the fiber around a very sharp radii after each pass. The fibers would likely break at every pass and jam up the extruder. Looks like the Mark Two can run in Isotropic Fiber mode to put down discrete fiber orientations. I think the Mark Two keeps the chamber hotter which might help keep the tow bundle from breaking. They also put the fiber cutter much closer to the extruder so the minimum cut area is 15x smaller per their literature. The cutter location distance to the extruder on the Mark One dictates the minimum filament length that has to be put down. The Mark Two might be able to cut the fiber at each pass before it changes direction eliminating the need to bend the filament. Haven’t seen the Mark Two in action yet, so I am only hypothesizing.
Well said, this is by far the best comment on the thread. I would only add an extra tidbit. The Mark one has a distance of just over 600mm between the cutter and the extruder. I believe the distance is 45mm on the Mark two.
That 3DXMax stuff is basically Nylon loaded with carbon fiber dust. It won’t even come close to the structural performance (stiffness and strength) that the Mark One or Two can deliver with continuous fiber. There is actually a fiber cutter in the Mark One and Two to cut the fibers.
But if that was the case regarding the carbon nano-fibers breaking then all other carbon filaments would also have had the same issue regarding minimum radius of curvature?
I do however think we are all being slightly ‘hoodwinked’ with so called ‘carbon fibre’ 3D printing… it does give nice results regarding print accuracy, warping and rigidity but strength doesn’t seem to be particularly elevated in any of my prints. Possibly even more brittle than some materials I have used.
One thing I did very much like about the MarkOne was that it could produce some epic nylon prints… very strong and very beautiful but for £5000 far too expensive to say the least.
you sound slightly irritated… I did add/say no offence intended and I did actually mean it… the MarkOne was a marketing triumph for MarkForged because it clearly funded MarkTwo with all of its absolutely critical upgrades. When I got that beauty home I was totally in love with it… after a week of trying to print with it I felt totally ripped off… I’d be disappointed with myself if I was not frank and honest here now that I have entered into a discussion about this printer.
Expensive marketing strategies can clearly go a long way.
Have to disagree with you on the weaving giving the strength to carbon fiber part. The weaving process actually degrades the basic structure performance of CFRP. Precisely because you are bending fibers when you weave it. A laminate of the same fiber and reinforcing plastic made from individual unidirectional layers will always be stronger and stiffer than a woven material. Looks pretty for car hoods though.
Which other carbon filaments are you referring? I am only aware of the Markforged printing continuous fiber. Plastics are often loaded with fillers to help stability. I wouldn’t bet on them necessarily improving structural performance. Loading nylons with glass particles or chopped carbon fiber should improved thermal expansion related issues.
I am pretty happy with the more structural parts I have made with my Mark One. It does require a bit more design/engineering understanding than your typical maker. Carbon is hardest to print.
Hanging my Jeep Hardtop with fiber reinforced printed parts.
Fantastic video… what a machine… however at 34 seconds in you can actually see the layers being put down diagonally in a ‘weave’ type finish? I used to work for Airbus where they helped to develop carbon fibre composites for aircraft wings so I have actually seen the process first hand. Weave/layer/lamination just semantics… I used the word ‘weave’ so everyone could grasp the point I was making…
You do have to tell the printer the fiber type you are loading. That is how it knows what fibers are loaded. I have noticed that it prints much more slowly with carbon. Pretty sure they have optimized speed and temperature uniquely for each fiber type. Also layer height is locked at 125mm for Carbon and 100mm for Kevlar. So clearly the fibers melt and spread differently. I’d bet you could tell the machine you are loading Carbon and load Kevlar instead to get 125mm Kevlar concentric layers, but it doesn’t surprise me that the other way around would not work. Unless you could manually slow the feed speed in Kevlar mode and increase layer height to 125mm. They don’t really let the user tweak those settings as far as I know.
Ah yes, semantics. Forget the technical lingo is different on the other side of the pond.
Excellent…Airbus has always been a me too company. Putting significant Carbon Fiber into the A350 only when customers complained that it wasn’t enough like the 787. I work for company B. Worked 787 development and currently work 777X. I see it everyday too. I always have to laugh at the Markforged marketing stating they were the first to 3D print continuous carbon fiber. The big boys have been doing it for a long time.
